Lifting jack



Dec. 15 1925. 1,565,878

J. M. WHITE IJIFTING JACK Filed June 12.5, 1924 Patented Dec. l5, 1925.

` UNITED STATES PATENT OFFICE.

JOHN M. WHITE, F EVANSTON, ILLINOIS, ABSIGNOB T0 WILLIAM E. PRATT, OF CHICAGO, ILLINOIS.

LLFTING JACK.

Application led Junev 13, 1924. Serial No. 719,735.

To all wlwm it may concern:

Be it known that I, JOHN M. lWHITE, a citizen v of the'United States, residing at Evanston, in the 'county of Cook and State of Illinois, have invented certain new and useful Improvements in Lifting J acks, of which the following is a specification.

This invention relates to lifting jacks and its purpose is to provide an improved jack having a relatively large vertical extension as compared with its normal helght. Such a jack. is particularly adantageous for use with automobiles equipped with balloon tires where the large diameter of the tire casing causes the axle to be lowered through a relatively great distance when the tire is deflated or blows out. This condition requires a jack having a comparatively short vertical dimension to permit its insertion beneath the axle when the tire is deflated and the vertical extension of the jack must be comparatively great in order to lift the tire casing o'the ground when it is inflated. The prmcipal object of the inventlon is to provide an improved jack of. the screw type adapted to meet the foregoing requirements. Another object is to provide a screw jack' having means for advancing the threaded member vertically Without vertical movement of the rotating member by which the vertical movement is effected. Still another object is to provide a jack having a plurality of screw threaded relatively eX- tensible members, each of which is held against rotative movement with'respect to the vthreaded member by which it is advanced longitudinally, thus making it possible to extend the parts of the jack or produce a reversed movement thereof without the necessity of holding the shoe or saddle which is adapted to engage the axle or other member to be lifted. Other objects relate to various features and construction of arrange ment which will appear more fully herein- 45 after. y

j The nature of the invention will be understood from the following specification taken with the accompanying drawings in whichone embodiment Ais illustrated. In the "o drawin Figure 1 shows a top plan view of the improved jack; Fig. 2 shows a sectional view on the line 2-2 of Fig. 1; and Fig. 3 shows a sectional view on the line 3-3 of Fig. 2.

As illustrated in the drawings, the jack comprises a substantially cylindrical hollow standard 10 provided at its lower end with a rectangular flange or basey 11 on which the jack is supported. The standard 10 is provided near its upper end with an internally threaded portion 12 engaged by the outer externally threaded supporting member 13. This supporting member is providedV on its outer side with a longitudinal keyway 111 which slidably' engages a key 15 secured to the worm wheel 16. This worm wheel is mounted within a housing 17 formed integrally with the upper part of the jack and it rests on the bearing surface 18 located above the threaded part 12 of the standard. The worm wheel 16vis actuated by a Worm 19 located in the lateral extension 17l of the housing and :formed integrally with a shaft 20 provided at one end with a socket 21. The shaft 20 is journaled at opposite ends of the worm 19 ,in bearings which are formed in the end walls of the housing portion 17a and the cover 22 thereof. The cover extends over the entire housing 17, enclosing the worm and worm wheel and being provided with a central aperture through which the supporting member 13 extends. The cover 22 is secured in place by means of'bolts 23 engaging the flanges 24. which project outwardly from the housing and the cover. Any desired form of handle may be employed in connection with the socket 21, but it is usually desirable to use a relatively long handle 25 having a hinged joint 26 between its ends and having a head 27, of non-circular cross section which engages the recess 28 in the socket 21'. The handle 25 is provided at its outer end with a transverse member 29 adapted to be engaged by the hands of the user. By means of this construction, the jack may be moved into position beneath the car axle without the necessity of the operator reaching under the automobile.

When the worm 19 is operated by the rotation of the handle 25, the resulting rotation of the worm 16 causes a corresponding rotation of the supporting member 13 and a resulting movement thereof in a vertical direction due to its engagement with the threaded portion 12 of the standard. As the worm wheel 16 rotates, the worm 13 slides on the key 15 and the supporting member is moved without any vertical movement of the operating mechanism comprising the worm and worm wheel and the handle 25,

The vertical movement of the standard 13 in an upward direction is limited by a. pin 30 which is secured in the lower end of the su porting member and adapted to engage t e shoulder 31 at the lower end of the threaded portion 12. The supporting member 13 is adapted to be moved into threaded engagement with the threaded portion l2, when the parts of the jack ere assembled, by passing 1t throu h an opening at the lower end of the stan ard 10, this opening being normally closed by a removable cover 33.

The jack also preferably comprises an inner externally threaded supporting member 35 which threadedly engages the internally threaded upper extremity 36 of the supporting'member 13, and the supporting member 35 carries et lts upper end e relatively fixed saddle or shoe 37 adapted to engage the underside of the cer axle or other object to be lifted. ln order to cause the inner supporting member 35 to be raised or lowered with respect to the outer supporting member 13 when the member 13 is rotated; the member 35 is provided with e controlling member 38 having a vertical extending portion 39 provided with e longitudinal slot 40 anda transverse portion 41, the extremities of which are adapted to slide loosel in vertical keyways 42 iormed in the stan ard 10. The controllin member 38 is passed into position throng thelower end of the standard which is normally closed by the cover 33 end the vertical stem 3Q thereo'r` is adapted to extend into the inner bore d3 oi? the inner supportin member 35, Where it slidably engages a xed transverse pin 44.

he engagement of the controlling member 38 with the lreytvays 42 and the pin 4A holds the inner supporting member 35 s einst rotation With respect to the standar 10 when the outer supporting member 13 is rotated so that the rotation ci the Worm Wheel 16 not only causes the outer supporting member 13 to advance with respect to the standard 10 but also causes the inner supporting member 35 to advance with respect to the outer supporting member 13. This construction is of particular advantage when it is desired to extend the parts of the jack or to Withdraw them into their coilspsed positions without the shoe 3? being 1n Contact with any stationary object. It will be -apparent that by means of this construction parts of the jack may be extended to a relatively great degree as compared with the height of the jack when the shoe 37 is in proximity to the housing cover 22.

Although one form of the jack has been shown and described byway of illustration, it will be understood that it may be constructed in various forms without departing from the scope of the appended claims.

I claim: l

1. A lifting jack comprising a, standard, s, supporting member having a threaded engagement with said standard and provided With a longitudinal keyway, said standard being provided in its upper part with a housing, a Worm Wheel mounted in Said housing and having a key engaging said keywa a worm mounted in said housing and meshing with said worm wheel, means for operating said worm, a second supporting member having a threaded engagement with said first-named supportin member, said second su porting member icing 'hollow, a control ing member having a stem adapted to extend into said hollow supporting member, said stem being slotted, a. pin fixed in said second supporting member and engaging said slotted controlling member, and s transverse member formed on said controlling member beneath said first-named supporting member, said first-named supporting member being provided on opposite sides thereof with keywnys adapted to be engaged by the ends of said transverse member.

2. A lifting jack comprising s standard, a supporting member having a threaded engagement with said standard, operating mechanism having s. fixed vertical position with respect to said standard for effecting rotation of said` supporting member, a second supporting mem er having a threaded engagement with seid rst supporting member, a controlling member comprising a vertical slotted portion and a transverse portion, and e pin engaging said second` supporting member and passing through said slotted portion, said standard having vertical keywsys engaged by said first transverse portion of said controlling member.

dHN M. WHITE.

lto 

